Hybrid vehicles and electric vehicles that carry a battery for driving the vehicle in the rear portion of the vehicle body are known from the literature. When a vehicle with this type of vehicle rear structure is struck from the back in a rear-end collision, for example, the battery can move forward, contact an appropriate member (such as a suspension member) located in front of the battery, and be deformed or damaged. This vehicle rear structure must therefore be constructed to avoid contact between members when the vehicle is struck from the back (is in a rear-end collision).
Japanese Patent Laid-open Publication No. 2006-205810 discloses a vehicle rear structure having a pair of side members that extend in a vehicle front-rear direction on opposite sides of the vehicle rear with the front ends of the side members lower than the back ends, a spare tire located between the back ends of the side members, and a fuel tank disposed on the vehicle front side of the spare tire.
By creating a low rigidity zone in this vehicle rear structure by forming a notch in each side member at a position between the spare tire and the fuel tank, the side members buckle starting from this low rigidity zone when the vehicle is hit in the rear, and the front end of the spare tire is relatively separated from the rear end of the fuel tank in the vehicle up-down direction.
With the vehicle rear structure used in some hybrid vehicles and electric vehicles, the battery unit is also known to straddle vertically the rear floor panel through an opening formed in the rear floor panel. The vehicle rear structure disclosed in Japanese Patent Laid-open Publication No. 2006-205810, however, is simply a means of preventing interference between the spare tire and the fuel tank in a rear-end collision.
More specifically, Japanese Patent Laid-open Publication No. 2006-205810 does not disclose a specific configuration in the vehicle rear structure that avoids contact between the battery unit and other obstructing members in a rear-end collision.
The present invention is directed to solving the foregoing problem by providing a vehicle rear structure that can protect the battery unit in a rear-end collision.